CyclinD1, known as a regulator of cyclin-dependent kinases, is indispensable in transition from G0/G1 phase to S phase and has been reported to serve as an oncogene in several types of cancers, including colorectal cancer (Wei et al., 2019), breast cancer (Hosseini et al., 2019) and osteosarcoma (Li et al., 2017). This evidence concerns the gene CCND1 and breast cancer.